CN109960859B - Vibration isolation structure and finite element simulation method for buildings along subway line - Google Patents
Vibration isolation structure and finite element simulation method for buildings along subway line Download PDFInfo
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- E—FIXED CONSTRUCTIONS
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Abstract
The invention relates to a vibration isolation structure of buildings along the subway and a finite element simulation method, belonging to the technical field of vibration isolation and vibration reduction of civil engineering. The steel rail is fixedly connected with the damping track bed through fasteners, damping base plates are arranged at the bottom of a foundation pit and on the side wall of the foundation pit of the building, and the damping base plates are laid at the bottom and on the side wall of the foundation pit with at least more than 50% of area; meanwhile, an isolation pile or a concrete isolation wall is arranged between the subway shield structure and the building foundation pit. By means of accurate finite element analysis simulation and actual measurement, vibration and noise of nearby buildings caused by subway induced vibration can be effectively solved, and indoor vibration meets the requirements of urban regional environmental vibration standard (GB 10070-88).
Description
Technical Field
The invention relates to a vibration isolation structure, in particular to a vibration isolation structure of buildings along the subway and a finite element simulation method, and belongs to the technical field of vibration isolation and vibration reduction of civil engineering.
Background
With the rapid development of rail traffic, the dynamic interaction between the rolling stock and the rail structure is increasingly enhanced, and the vibration problem of the adjacent buildings caused thereby is also more serious. When a train runs along a track line, the vehicle-track system vibrates due to the dynamic load of wheels and tracks excited by the irregularity of the track, and the vibration is radiated and transmitted to a far soil body through a railway ballast and a roadbed, so that buildings around the track vibrate. The coupled vibration of a train, a track structure, a station building structure, an upper building structure and a surrounding soil body belongs to the power problem of a large-scale complex open system, wherein the wheel-track interaction is a connecting link of the train and an engineering structure, so that the whole system can be decomposed into a train-track coupled subsystem and a track-station building structure-soil body coupled subsystem. The train-track coupling subsystem obtains an exciting force acting on a track structure, namely a vibration source part; and applying the exciting force to the track-station house-soil body coupling subsystem for vibration reaction analysis.
During the operation of the subway, the generated vibration is diffused and propagated to the surrounding soil body through the subway foundation and then propagated to the building foundation and the superstructure through the foundation. The superstructure can produce secondary vibration and noise after receiving subway induced vibration, influences normal use and travelling comfort. Therefore, it is necessary to analyze the subway induced vibration and take some vibration reduction and isolation measures.
Disclosure of Invention
In order to solve the defects in the prior art, the invention provides a vibration isolation structure of a building along a subway line and a finite element simulation method, which are used for solving the problems of vibration and noise influence and simulation caused by subway-induced vibration on adjacent buildings.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
the subway line building vibration isolation structure comprises an existing subway tunnel shield structure and a building, wherein a track bed is arranged in the existing subway tunnel shield structure, a steel rail is paved on the track bed, the steel rail is fixedly connected with the track bed through a fastener, vibration damping base plates are arranged at the bottom of a foundation pit of the building and on the side wall of the foundation pit, and the vibration damping base plates are paved at the bottom and on the side wall of the foundation pit with the area of at least more than 50%; meanwhile, an isolation pile or a concrete isolation wall is arranged between the subway shield structure and the building foundation pit.
Furthermore, the diameter of the isolation pile is 0.5-1m, the pile distance is 0.5-1.3m, the two sides of the isolation pile in the horizontal direction exceed the edge of the foundation pit and are respectively greater than 5m, and the depth of the isolation pile in the vertical direction exceed the shield structure of the subway tunnel is greater than 5m.
Furthermore, the isolation piles are arranged in two rows and are arranged in a staggered mode.
Furthermore, the width of the concrete isolation wall is 1-1.5m, the length of the concrete isolation wall is 50-80m, the depth of the concrete isolation wall is 25-50m, the distance from two sides of the concrete isolation wall to the edge of the foundation pit in the horizontal direction is greater than 5m, and the distance from the concrete isolation wall to the shield structure of the existing subway tunnel in the vertical direction is greater than 5m.
Further, the thickness of the damping base plate at the bottom of the foundation pit is not less than 25mm, and the thickness of the damping base plate on the side wall of the foundation pit is not less than 20mm.
Furthermore, the vibration damping base plate is a rubber vibration damping support and a rubber foam plate.
Further, the vibration damping backing plate is connected with the gypsum boards at the bottom and on the side wall of the foundation pit.
Furthermore, an isolation trench is arranged between the subway shield structure and the building foundation pit, the depth of the isolation trench is determined according to the wavelength of the surface wave generated by subway vibration, and the depth of the isolation trench is not less than the wavelength of the surface wave; the two sides of the vibration isolation trench in the horizontal direction exceed the edge of the foundation pit and are respectively larger than 5m, and the depth of the vibration isolation trench in the vertical direction exceeds the depth of the shield structure of the existing subway tunnel and is larger than 5m.
Furthermore, the track bed is a steel spring floating plate vibration reduction track bed.
The finite element simulation method of the vibration isolation structure of the buildings along the subway line comprises the following steps
Basic assumption
Before establishing a finite element numerical simulation model, the following simplifying assumptions are made:
(1) The soil body is assumed to be an elastic constitutive body under weak excitation of rail transit;
(2) The soil body is considered as a horizontal layered system, and each layer of soil body consists of the same medium and is isotropic;
(3) Ignoring the microstructure of soil particles, considering that the spatial change of the stress strain and the physical displacement of the soil medium can be described by a continuous function;
(II) grid cell size
When the dynamic response finite element method is adopted to carry out semi-infinite domain dynamic analysis, because the essence of the problem is the solution of a stress wave field, a reasonable finite element model needs to reflect the propagation characteristics of the stress wave, the fluctuation effect in a medium can be captured, and the discretization of a half-space soil body is required to meet certain conditions;
because the propagation speed of the wave is limited, the response of any node in the finite element discrete grid at a certain moment is determined by the responses of nodes in the adjacent area at the previous moment and a plurality of previous moments, and the discretization method of the finite element model must embody the fluctuation characteristics of the continuous medium body as much as possible; when a discrete model is adopted to replace a continuous medium, the propagation rule of the elastic wave changes to a certain extent, which is caused by the fact that the propagation phase velocity of the plane wave in a discrete grid is not equal to the physical wave velocity of the plane wave but is related to the propagation direction and frequency of the wave, and additional frequency dispersion of the discrete model is generated; meanwhile, the waves in the discrete model have cut-off frequency, and the wave energy exceeding the cut-off frequency cannot be propagated and is mixed in the low-frequency waves in a parasitic oscillation mode; in order to ensure the calculation precision and control the frequency dispersion and improve the cut-off frequency, when a discrete model is adopted to analyze the fluctuation problem, the unit size division is required to be not too large; on the premise of considering the factors, unnecessary calculation amount is reduced as much as possible, and the grid division size in the concerned range and the key position of the model is planned in detail in a density-sparse combination mode so as to meet the precision requirement of the calculation model;
(III) boundary conditions
When a semi-infinite rock-soil body is simulated by adopting a discrete model in a limited range, the reflection of stress waves occurs on the intercepted model boundary, so that a real wave field is interfered, and the simulation result is distorted; the finite element model adopts a viscoelastic artificial boundary condition which can simultaneously simulate scattered wave radiation and foundation elastic recovery performance; the three-dimensional viscoelastic dynamic artificial boundary is equivalently simulated by arranging a continuously distributed parallel spring-damper system on an artificially truncated boundary;
the calculation formulas of the elastic coefficient of the spring element and the damping coefficient of the viscous damper are shown as the following formulas.
In the formula: ρ and G represent the mass density and shear modulus of the medium, respectively; r represents the distance from the wave source to the artificial boundary; c represents the wave velocity in the medium, the normal artificial boundary wave velocity is taken as the longitudinal wave velocity, and the tangential artificial boundary wave velocity is taken as the shear wave velocity; the parameter alpha is valued according to the type and the setting direction of the artificial boundary;
in the practical application of the viscoelastic artificial boundary condition in the finite element model, the spring unit and the damper unit which are connected in parallel are only required to be respectively arranged in the normal direction and the tangential direction of the artificial boundary node of the finite element model, and the parameters of the spring unit and the damper unit can be determined according to the following formula.
In the formula: a. The i The boundary represented by the artificial boundary node.
(IV) analysis method and calculation step length
The subway vibration numerical calculation adopts a direct integration method in transient dynamics analysis, the method is directly based on a general dynamics equation, the considered time history is subjected to equal-time-interval discrete division, the vibration response of the next moment is calculated from the previous moment according to the known initial conditions, namely displacement, speed, acceleration and load, the time history of the displacement, stress, strain, speed and acceleration variables of the structure under the action of the load can be obtained, the increment between two adjacent time points is called as an integration time step, a finite element calculation program usually adopts an implicit newmark-beta time integration method, and the method also comprises an explicit central difference method and an implicit wilson-theta method;
the time step of the direct integration method directly influences the calculation and analysis precision, and when the vibration wave propagation problem is solved in the time domain, high-frequency components are lost due to too large step, so that the precision is reduced; the step length is too small, the calculation steps are increased, and the solving efficiency is reduced, so that after the frequency domain post-processing precision and the computer operation capacity are balanced and considered, the simulation model calculation time step length is 1/512s, the highest analysis frequency is more than 200Hz, and the vibration level data processing requirement is met;
and (V) performing simulation modeling analysis by adopting MIDAS or ABAQUS.
Compared with the prior art, the invention has the following technical effects:
the vibration isolation structure of the building along the subway and the finite element simulation method can effectively attenuate the influence of subway vibration on the building, play a good role in filtering, reduce the influence of vibration and noise of the building and meet environmental standards and personnel comfort.
Drawings
FIG. 1 is a schematic view of a vibration isolation structure of a building along a subway line in the invention;
FIG. 2 is a schematic diagram of a shield structure of a subway tunnel;
FIG. 3 is a top view of a finite element model of a foundation soil mass;
figure 4 is a side view of a finite element model of a foundation soil.
Detailed Description
The following description of the embodiments of the present invention will be made in detail with reference to the accompanying drawings 1 to 4.
Example 1
As shown in fig. 1-2, a building in a certain place is less than 7 meters away from the subway line, and the vibration and noise influence is serious. In order to solve the problem, the vibration isolation structure for the buildings along the subway line is designed, and comprises an existing subway tunnel shield structure 1 and a building 2, wherein a steel spring floating plate vibration reduction ballast bed 3 is arranged in the existing subway tunnel shield structure 1, a steel rail 7 is paved on the vibration reduction ballast bed 3, the steel rail 7 is fixedly connected with the vibration reduction ballast bed 3 through a fastener, vibration reduction base plates 5 are arranged at the bottom of a foundation pit and on the side wall of the foundation pit of the building, and the vibration reduction base plates 5 are paved at 70% of the bottom of the foundation pit and on the side wall of the foundation pit. Meanwhile, an isolation pile 4 is also arranged between the subway shield structure 1 and the foundation pit of the building 2. The diameter of each isolation pile is 0.8m, the pile distance is 1.3m, the two sides of each isolation pile in the horizontal direction exceed the edges of the foundation pit by 6m respectively, and the depth of each isolation pile in the vertical direction exceeds the depth of the shield structure of the subway tunnel by 6m. The isolation piles are arranged in two rows and are arranged in a staggered mode. The thickness of the damping base plate at the bottom of the foundation pit is 30mm, and the thickness of the damping base plate on the side wall of the foundation pit is 25mm. The damping backing plate adopts the cotton board of rubber bubble, and the damping backing plate is connected with the gypsum board of foundation ditch bottom and lateral wall. In addition, the vibration isolation trench 6 is arranged between the subway shield structure and the foundation pit of the building, two sides of the vibration isolation trench 6 in the horizontal direction exceed the edge of the foundation pit by 6m respectively, the depth of the vibration isolation trench 6 is determined according to the wavelength of a surface wave generated by subway vibration, the depth of the vibration isolation trench is not less than the wavelength of the surface wave (20 m in the embodiment), and the vertical direction of the vibration isolation trench exceeds the depth of the existing subway tunnel shield structure by 5.5m.
As shown in fig. 3-4, the finite element simulation method for vibration isolation structure of buildings along subway line includes the following steps
Basic assumption
Before establishing a finite element numerical simulation model, the following simplifying assumptions are made:
(1) The soil body is assumed to be an elastic constitutive body under the weak excitation of rail transit.
(2) The soil body is considered as a horizontal layered system, and each layer of the soil body consists of the same medium and is isotropic.
(3) Neglecting the microstructure of soil particles, the spatial variation of the stress strain and physical displacement of the soil medium can be described by a continuous function.
(II) grid cell size
When the dynamic response finite element method is adopted to carry out semi-infinite domain dynamic analysis, because the essence of the problem is the solution of a stress wave field, a reasonable finite element model needs to reflect the propagation characteristic of the stress wave, the fluctuation effect in a medium can be captured, and the discretization of a half-space soil body is required to meet certain conditions.
Because the propagation velocity of the wave is limited, the response of any node in the finite element discrete grid at a certain moment is determined by the responses of nodes in the adjacent area of the node at the previous moment and a plurality of previous moments, and the discretization method of the finite element model must embody the wave characteristics of the continuous medium body as much as possible. When a discrete model is used instead of a continuous medium, the propagation law of the elastic wave changes to some extent, which is caused by the fact that the propagation phase velocity of a plane wave in a discrete grid is no longer equal to the physical wave velocity thereof, but depending on the propagation direction and frequency of the wave, additional dispersion of the discrete model is generated. Meanwhile, the waves in the discrete model have a cut-off frequency, and the wave energy exceeding the cut-off frequency cannot propagate but is mixed in the low-frequency waves in a parasitic oscillation manner. In order to ensure the calculation precision and control the dispersion and improve the cut-off frequency, when a discrete model is adopted to analyze the fluctuation problem, the unit size division is required to be not too large. On the premise of considering the factors, unnecessary calculation amount is reduced as much as possible, and the grid division size in the concerned range and the key position of the model is planned in detail in a sparse-dense combination mode so as to meet the precision requirement of the calculation model.
(III) boundary conditions
When a semi-infinite rock-soil body is simulated by adopting a discrete model in a limited range, the reflection of stress waves occurs on the intercepted model boundary, so that a real wave field is interfered, and the simulation result is distorted. The finite element model adopts a viscoelastic artificial boundary condition which can simultaneously simulate scattered wave radiation and the elastic recovery performance of the foundation. The three-dimensional viscoelastic dynamic artificial boundary is equivalently simulated by arranging a continuously distributed parallel spring-damper system on the boundary which is artificially truncated.
The calculation formulas of the elastic coefficient of the spring element and the damping coefficient of the viscous damper are shown as the following formulas.
In the formula: ρ and G represent the mass density and shear modulus of the medium, respectively. R represents the distance of the wave source to the artificial boundary. c represents the wave velocity in the medium, the normal artificial boundary wave velocity is the longitudinal wave velocity, and the tangential artificial boundary wave velocity is the shear wave velocity. The parameter alpha is valued according to the type and the setting direction of the artificial boundary.
In the practical application of the viscoelastic artificial boundary condition in the finite element model, the spring unit and the damper unit which are connected in parallel are only needed to be respectively arranged in the normal direction and the tangential direction of the artificial boundary node of the finite element model, and the parameters of the spring unit and the damper unit can be determined according to the following formula.
In the formula: a. The i The boundary represented by the artificial boundary node.
(IV) analysis method and calculation step length
The subway vibration numerical calculation adopts a direct integration method in transient dynamics analysis, the method is directly based on a general dynamics equation, the considered time history is divided into discrete time intervals, the vibration response of the next moment is calculated from the previous moment according to the known initial conditions, namely displacement, speed, acceleration and load, the time history of the displacement, stress, strain, speed and acceleration variables of the structure under the action of the load can be obtained, the increment between two adjacent time points is called as an integration time step, a finite element calculation program usually adopts an implicit newmark-beta time integration method, and the method also comprises an explicit central difference method and an implicit wilson-theta method.
The time step of the direct integration method directly influences the calculation and analysis precision, and when the vibration wave propagation problem is solved in the time domain, high-frequency components are lost due to too large step, so that the precision is reduced. The too small step length increases the calculation step number and reduces the solving efficiency, so that after the frequency domain post-processing precision and the computer operation capacity are balanced and considered, the simulation model calculation time step length is 1/512s, the highest analysis frequency is more than 200Hz, and the vibration level data processing requirement is met.
And (V) performing simulation modeling analysis by adopting MIDAS or ABAQUS.
And (3) analyzing an actual measurement result:
table 1 shows the measured indoor vibration values of each floor using the damping shim plate 5 of 70%.
TABLE 1
| Floor level | Maximum Z vibration level Vlzmax | The superscalar (daytime) is more than or equal to 70dB | Over-standard (night) not less than 67dB |
| F1 | 65.4 | -- | -- |
| F2 | 64.4 | -- | -- |
| F3 | 64.3 | -- | -- |
| F4 | 64.3 | -- | -- |
| F5 | 64.2 | -- | -- |
| F6 | 63.6 | -- | -- |
| F7 | 63.8 | -- | -- |
| F8 | 63.7 | -- | -- |
| F9 | 63.7 | -- | -- |
| F10 | 63.2 | -- | -- |
| F11 | 62.9 | -- | -- |
| F12 | 62.8 | -- | -- |
| F13 | 62.8 | -- | -- |
| F14 | 62.7 | -- | -- |
| F15 | 62.7 | -- | -- |
| F16 | 63.0 | -- | -- |
| F17 | 63.2 | -- | -- |
| F18 | 63.2 | -- | -- |
| F19 | 63.1 | -- | -- |
| F20 | 63.5 | -- | -- |
| F21 | 63.1 | -- | -- |
| F22 | 63.1 | -- | -- |
| F23 | 64.4 | -- | -- |
| F24 | 64.4 | -- | -- |
| F25 | 64.5 | -- | -- |
Shown by table 1, when the damping backing plate 5 is adopted to 70% of the part of foundation ditch bottom and lateral wall, be close to subway tunnel shield structure 1 one side with above-mentioned 70% damping backing plate 5 setting, its building indoor vibration all can satisfy among "urban area environmental vibration standard" (GB 10070-88): the standard limit requirements of 70DB and 67DB in daytime of residents and cultural and educational areas are met, and good vibration reduction and noise reduction effects are achieved.
Example 2
In this embodiment, the concrete isolation wall 4 is used to replace the isolation pile 4 in embodiment 1, the width of the concrete isolation wall 4 is 1.5m, the length is 60m, and the depth is 30m, the two sides of the concrete isolation wall 4 in the horizontal direction exceed the edge of the foundation pit respectively by more than 5m, and the depth exceeding the existing subway tunnel shield structure in the vertical direction is more than 5m. The other structure setting and simulation methods are the same as those of embodiment 1. Through actual measurement, the vibration reduction and noise reduction effects can be better.
The above-mentioned embodiments are only given for the purpose of more clearly illustrating the technical solutions of the present invention, and are not meant to be limiting, and variations of the technical solutions of the present invention by those skilled in the art based on the common general knowledge in the art are also within the scope of the present invention.
Claims (9)
1. The method comprises the following steps of (1) simulating a finite element of a vibration isolation structure of a building along the subway line, wherein the vibration isolation structure of the building along the subway line comprises an existing subway tunnel shield structure and the building, a track bed is arranged in the existing subway tunnel shield structure, a steel rail is laid on the track bed and fixedly connected with the track bed through a fastener, vibration damping base plates are arranged at the bottom of a foundation pit of the building and the side wall of the foundation pit, and the vibration damping base plates are laid at the bottom and the side wall of the foundation pit with the area of at least more than 50%; meanwhile, an isolation pile or a concrete isolation wall is arranged between the subway shield structure and the building foundation pit;
the method is characterized by comprising the following steps:
basic assumption
Before establishing a finite element numerical simulation model, the following simplifying assumptions are made:
(1) The soil body is assumed to be an elastic constitutive body under weak excitation of rail transit;
(2) The soil body is considered as a horizontal layered system, and each layer of soil body consists of the same medium and is isotropic;
(3) Ignoring the microstructure of soil particles, considering that the spatial change of the stress strain and the physical displacement of the soil medium can be described by a continuous function;
(II) grid cell size
When the dynamic response finite element method is adopted to carry out semi-infinite domain dynamic analysis, because the essence of the problem is the solution of a stress wave field, a reasonable finite element model needs to reflect the propagation characteristics of the stress wave, the fluctuation effect in a medium can be captured, and the discretization of a half-space soil body is required to meet certain conditions;
because the propagation speed of the wave is limited, the response of any node in the finite element discrete grid at a certain moment is determined by the responses of nodes in the adjacent area at the previous moment and a plurality of previous moments, and the discretization method of the finite element model must embody the fluctuation characteristics of the continuous medium body as much as possible; when a discrete model is adopted to replace a continuous medium, the propagation rule of the elastic wave changes to a certain extent, which is caused by the fact that the propagation phase velocity of a plane wave in a discrete grid is not equal to the physical wave velocity of the plane wave but is related to the propagation direction and frequency of the wave, and additional frequency dispersion of the discrete model is generated; meanwhile, the waves in the discrete model have cut-off frequency, and the wave energy exceeding the cut-off frequency cannot be propagated and is mixed in the low-frequency waves in a parasitic oscillation mode; in order to ensure the calculation precision, control the frequency dispersion and improve the cut-off frequency, when a discrete model is adopted to analyze the fluctuation problem, the unit size division is required to be not too large; on the premise of considering the factors, unnecessary calculation amount is reduced as much as possible, and the grid division size in the concerned range and the key position of the model is planned in detail in a sparse-dense combination mode so as to meet the precision requirement of the calculation model;
(III) boundary conditions
When a semi-infinite rock-soil body is simulated by adopting a discrete model in a limited range, the reflection of stress waves occurs on the intercepted model boundary, so that a real wave field is interfered, and the simulation result is distorted; the finite element model adopts a viscoelastic artificial boundary condition which can simultaneously simulate scattered wave radiation and foundation elastic recovery performance; the three-dimensional viscoelastic dynamic artificial boundary is equivalently simulated by arranging a continuously distributed parallel spring-damper system on an artificially truncated boundary;
the calculation formula of the elastic coefficient of the spring element and the damping coefficient of the viscous damper is shown as the following formula:
in the formula: ρ and G represent the mass density and shear modulus of the medium, respectively; r represents the distance from the wave source to the artificial boundary; c, representing the wave velocity in the medium, wherein the normal artificial boundary wave velocity is the longitudinal wave velocity, and the tangential artificial boundary wave velocity is the shear wave velocity; the parameter alpha is valued according to the type and the setting direction of the artificial boundary;
in the practical application of the viscoelastic artificial boundary condition in the finite element, the spring unit and the damper unit which are connected in parallel are only needed to be respectively arranged in the normal direction and the tangential direction of the artificial boundary node of the finite element model, and the parameters of the spring unit and the damper unit can be determined according to the following formula:
in the formula: a. The i A boundary represented by an artificial boundary node;
(IV) analysis method and calculation step length
The subway vibration numerical calculation adopts a direct integration method in transient dynamics analysis, the method is directly based on a general dynamics equation, the considered time history is subjected to equal-time-interval discrete division, the vibration response of the next moment is calculated from the previous moment according to the known initial conditions, namely displacement, speed, acceleration and load, the time history of the displacement, stress, strain, speed and acceleration variables of the structure under the action of the load can be obtained, the increment between two adjacent time points is called as an integration time step, a finite element calculation program usually adopts an implicit newmark-beta time integration method, and the method also comprises an explicit central difference method and an implicit wilson-theta method;
the time step of the direct integration method directly influences the calculation and analysis precision, and when the vibration wave propagation problem is solved in the time domain, high-frequency components are lost due to too large step, so that the precision is reduced; the step length is too small, the calculation steps are increased, and the solving efficiency is reduced, so that after the frequency domain post-processing precision and the computer operation capacity are balanced and considered, the simulation model calculation time step length is 1/512s, the highest analysis frequency is more than 200Hz, and the vibration level data processing requirement is met;
and (V) performing simulation modeling analysis by adopting MIDAS or ABAQUS.
2. The finite element simulation method of the vibration isolation structure of the buildings along the subway line as claimed in claim 1, wherein: the diameter of the isolation pile is 0.5-1m, the pile distance is 0.5-1.3m, the two sides of the isolation pile in the horizontal direction exceed the edge of the foundation pit and are respectively greater than 5m, and the depth of the isolation pile in the vertical direction exceed the shield structure of the subway tunnel is greater than 5m.
3. The finite element simulation method of the vibration isolation structure of the buildings along the subway line as claimed in claim 2, wherein: the isolation piles are arranged in two rows and are arranged in a staggered mode.
4. A finite element simulation method of vibration isolation structures of buildings along the subway according to claim 1, wherein: the width of the concrete isolation wall is 1-1.5m, the length of the concrete isolation wall is 50-80m, the depth of the concrete isolation wall is 25-50m, the two sides of the concrete isolation wall in the horizontal direction exceed the edge of the foundation pit and are respectively more than 5m, and the depth of the concrete isolation wall in the vertical direction exceed the shield structure of the existing subway tunnel is more than 5m.
5. The finite element simulation method of the vibration isolation structure of the buildings along the subway line as claimed in claim 1, wherein: the thickness of the damping base plate at the bottom of the foundation pit is not less than 25mm, and the thickness of the damping base plate on the side wall of the foundation pit is not less than 20mm.
6. A finite element simulation method of vibration isolation structures of buildings along the subway according to claim 5, wherein the finite element simulation method comprises the following steps: the vibration damping base plate is a rubber vibration damping support and a rubber foam plate.
7. A finite element simulation method of a vibration isolation structure of a building along a subway according to claim 6, wherein: the vibration reduction backing plate is connected with the gypsum boards at the bottom and the side wall of the foundation pit.
8. A finite element simulation method of vibration isolation structures of buildings along the subway line according to any one of claims 1 to 7, wherein: the method comprises the following steps that an isolation trench is arranged between a subway shield structure and a building foundation pit, the depth of the isolation trench is determined according to the wavelength of a surface wave generated by subway vibration, and the depth of the isolation trench is not smaller than the wavelength of the surface wave.
9. A finite element simulation method of vibration isolation structures of buildings along the subway line according to any one of claims 1 to 7, wherein: the ballast bed is a steel spring floating plate vibration reduction ballast bed.
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| CN112922041B (en) * | 2021-02-02 | 2022-07-15 | 北京城建北方集团有限公司 | Vibration reduction construction process for underground rail transit approach building |
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| CN113962127B (en) * | 2021-10-22 | 2024-07-30 | 北京市科学技术研究院城市安全与环境科学研究所 | Rapid estimation method for vibration reduction efficiency of vertical wave barrier |
| CN114112262B (en) * | 2021-11-18 | 2023-08-15 | 中国铁路设计集团有限公司 | Floor spraying fiber vibration chip falling test method under overhead line of rail transit |
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